At about 12:01 AM, Sunday, March 9, 2014, officers from District A-1 (Downtown) responded to a radio call for a person with a knife in the area of Hanover Street and Blackstone Street in the Downtown area.

On arrival, officers observed an unknown male lying on the ground pinned by another male. As officers approached the two individuals, they observed that the male victim (who had been pinning the suspect to the ground) appeared to be suffering from stab wounds and had been detaining the suspect until police arrived. Officers immediately placed the suspect under arrest. Upon further investigation, officers learned that the victim had witnessed the suspect attempting to assault an unknown female. In an effort to assist the female victim, the male victim attempted to intervene. An altercation took place during which the suspect pulled a knife and stabbed the victim. The victim was able to knock the knife away from the suspect and further detain him until officers arrived. The knife was later recovered in a nearby sewer.

John Driscoll, 29, of Jamaica Plain was arrested and charged with Assault with Intent to Murder, Assault by Means of a Dangerous Weapon - Knife, and Assault and Battery.